1. Field of the Invention
The invention relates to an interface device for exchanging data between a first bus system and a second bus system, where an input/output device is connectable to the second bus system and an addressable slot and an addressable subslot is located within the input/output device for outputting or receiving input/output data, and where the interface device comprises a first transceiver device for the data of the first bus system, a second transceiver device for the data of the second bus system, a data transfer to device with a transfer memory, and a control device configured to control the data storage and coordinate write accesses into or at the data transfer device.
2. Description of the Related Art
In automation technology, there is particularly an exchange of payload data, i.e., input and output data from components to be automated such as machines, actuator drives or sensors, between input/output devices such as modular decentralized peripheral systems for example and higher-ranking automation devices via field buses. Known examples of field buses are Profibus or Profinet. Within an input/output device of a decentralized peripheral station, payload data can be distributed to individual modules or read out from the individual modules. The field bus and the backplane bus system generally operate asynchronously in relation to one another and an updating of data, for example, of a subslot payload data packet, is also only possible in some cases. As a reusit, a buffer is necessary to ensure data consistency between the two bus systems.
Such buffers, or also alternating buffers, are known from the European patent application EP 1 253 494 B1. In the known open-loop and/or closed-loop control system where via a field bus a decentralized peripheral is accessed, it is disadvantageous that it can no longer keep pace with the current speed demands made on payload data exchanges.